1. Field of the Invention
The present invention relates to a composition comprising a plant and a specific polymer having water absorbing properties that contains water, which composition enables the plant to grow therein. More particularly, the present invention relates to a composition which enables continuous growth therein of a plant which is able to grow in the presence of at least water and light, by having the plant coexist with a nonionic water-absorptive polymer which absorbs at least water, particularly N-vinyl carboxylic amide polymer, more particularly N-vinyl acetamide polymer.
2. Description of the Related Art
As is well known, the consumption of fossil fuels, typified by petroleum and coal, has recently been increasing drastically due to human activities, resulting in a rapid increase in carbon dioxide concentration in the atmosphere.
The balance in the amounts of atmospheric oxygen and carbon dioxide has mainly been preserved by plant resources. However, this balance is being lost by the drastic increase in carbon dioxide due to deforestation as well as the aformentioned circumstances.
It is predicted that the drastic increase in carbon dioxide in the atmosphere will greatly affect the earth's climate in the near future due to the so-called greenhouse effect.
Throughout the world, there have been made attempts to slow down the increase in atmospheric carbon dioxide concentration, such as control of automobile emissions and preservation and improvement of the environment, including forests, but none of these attempts have succeeded.
As mentioned above, plant resources are the primary factor in preserving the balance in the amounts of atmospheric oxygen and carbon dioxide, but the consumption of forest resources is unavoidable in the maintenance of civilization as we know it. Therefore, indiscriminate deforestation has continued unabatedly and recovery of forest resources is far from catching up with deforestation.
In view of the foregoing, relatively lower plants such as phytoplankton, marine plants, and Bryophyta are of interest.
First, lower plants provide excellent absorption efficiency of carbon dioxide because, unlike the tree, they don't have large bodies consisting of cellulosic skeletons. Secondly, these plants are considered suitable for bulk use in factories and plant facilities where large amounts of carbon dioxide are produced. Also, unlike terrestrial plants, many of these plants have an advantage in that they can grow in harsh environments.
Accordingly, there have been made various attempts to use the aforementioned phytoplankton and the like having these properties as a means to recover the balance in the amounts of atmospheric oxygen and carbon dioxide. However, none of the attempts have been put into full-scale practical use, because growing the aforementioned phytoplankton and the like continuously and having them perform photosynthesis efficiently would require large-scale facilities which permit continuous stirring.
In order to realize recovery of the balance in the amounts of atmospheric oxygen and carbon dioxide by use of the aforementioned plants, there must be provided a means to collect as much phytoplankton and the like as possible and to have them perform photosynthesis efficiently.
One plausible means for this is to immobilize the aforementioned phytoplankton alive. This immobilization requires a carrier which permits immobilization of the aforementioned phytoplankton alive.
As a carrier for this immobilization, mention is given first of water-absorptive polymers.
Water-absorptive polymers are currently classified into three classes; i.e. starch, cellulosic, and synthetic polymers, and all these provide excellent water absorbing abilities.
However, when water-absorptive polymers are caused to absorb water and then are permitted to come into contact with phytoplankton and the like, none of the polymers are able to grow the phytoplankton and the like continuously, letting the phytoplankton and the like be killed in a short time.